The purpose of this study was to investigate students\u27 conceptions of the greenhouse effect, global warming, and climate change. The study was descriptive in nature and reflected a cross-age design involving the collection of qualitative data from 51 secondary students from three different schools in the Midwest, USA. These data were analyzed for content in an inductive manner to identify student\u27s conceptions. The categories that emerged from the students\u27 responses reflected different degrees of sophistication of students\u27 conceptions about the greenhouse effect, global warming, and climate change. Based on these findings we make curricular recommendations that build on the students\u27 conceptions, the IPCC Findings, the NRC (1996) science education standards, and NOAA\u27s climate literacy framework